Water Pump Impeller for Honda 8, 9.9, 15 & 20 HP 4-Stroke Outboards – Replaces 19210-ZW9-A31/19210-ZW9-A32
Water Pump Impeller for Honda 8, 9.9, 15 & 20 HP 4-Stroke Outboards – Replaces 19210-ZW9-A31/19210-ZW9-A32 is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
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Water Pump Impeller for Honda 8, 9.9, 15 & 20 HP 4-Stroke Outbo...
Water Pump Impeller for Honda 8, 9.9, 15 & 20 HP 4-Stroke Outboards – Replaces 19210-ZW9-A31/19210-ZW9-A32 is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket water pump impeller is designed for Honda 4-stroke outboard engines rated at 8, 9.9, 15, and 20 HP. It is a single replacement impeller for restoring water-pump circulation and helping maintain proper engine cooling.
The impeller replaces Honda OEM part numbers 19210-ZW9-A31 and 19210-ZW9-A32. It is also identified as a replacement for Sierra Marine 18-32455.
- Replacement impeller for Honda Marine 4-stroke outboards.
- Single-item replacement for the water pump impeller.
- Designed for the Honda horsepower and year ranges listed below.
- Inspect the existing key, gasket, housing, and wear plate before installation; those components are not included with this impeller.
Part Number Matrix
Use these manufacturer and aftermarket references when comparing your existing impeller.
| Brand | Part Number | Reference Type |
|---|---|---|
| Honda | 19210-ZW9-A31 | OEM replacement reference |
| Honda | 19210-ZW9-A32 | OEM replacement reference |
| Sierra Marine | 18-32455 | Aftermarket reference |
Engine Compatibility
Company fitment identifies this impeller for Honda 4-stroke outboards in the following horsepower and year ranges. Confirm the exact engine model and the part number on your original impeller before ordering.
| Brand | Rated HP | Stroke | Year Range | OEM Part Numbers |
|---|---|---|---|---|
| Honda | 8 | 4-Stroke | 2001 and newer | 19210-ZW9-A31 / 19210-ZW9-A32 |
| Honda | 9.9 | 4-Stroke | 2001 and newer | 19210-ZW9-A31 / 19210-ZW9-A32 |
| Honda | 15 | 4-Stroke | 2003 and newer | 19210-ZW9-A31 / 19210-ZW9-A32 |
| Honda | 20 | 4-Stroke | 2003 and newer | 19210-ZW9-A31 / 19210-ZW9-A32 |
Technical Specifications
- Product Type
- Water pump impeller
- Application
- Honda Marine 4-stroke outboard engines
- Rated Engine Range
- 8, 9.9, 15, and 20 HP
- Installation
- Replacement impeller for the existing water-pump assembly
- Aftermarket Reference
- Sierra Marine 18-32455
- OEM References
- Honda 19210-ZW9-A31 and 19210-ZW9-A32
What's in the Box
- 1 x Water pump impeller
This listing is for the impeller only. A drive key, gaskets, O-rings, wear plate, and water-pump housing are not included unless separately stated.
Installation Notes
- Disconnect the battery and follow the service manual for your specific Honda outboard.
- Remove the lower unit and water-pump housing according to the manufacturer's procedure.
- Remove the old impeller and retain the drive key if it is reusable.
- Inspect the water-pump housing, wear plate, drive key, and sealing components for wear, scoring, corrosion, or damage.
- Clean the pump area before installing the replacement impeller.
- Install the impeller with the correct drive-key engagement and fin orientation specified by the engine service manual.
- Reinstall the water-pump housing and lower unit using the manufacturer's tightening specifications.
- Run the engine using the correct water supply procedure and verify a strong cooling-water discharge before normal operation.
Troubleshooting & FAQ
How do I know if this impeller fits my Honda outboard?
This impeller is listed for Honda 4-stroke outboards rated at 8, 9.9, 15, and 20 HP. The listed year ranges are 2001 and newer for 8 and 9.9 HP engines, and 2003 and newer for 15 and 20 HP engines. Confirm the exact engine model and the OEM part number before installation.
Which Honda part numbers does this impeller replace?
The listed Honda replacement references are 19210-ZW9-A31 and 19210-ZW9-A32. Sierra Marine reference 18-32455 is also associated with this impeller application.
Is this a complete water-pump repair kit?
No. This product is a single water pump impeller. Gaskets, O-rings, the drive key, wear plate, and housing are not included.
Is the drive key included?
No. The package contains one impeller only. Inspect the existing drive key and replace it separately if it is worn, damaged, or missing.
What are signs of a worn water-pump impeller?
Possible signs include reduced or intermittent cooling-water discharge, overheating, or visible cracking, brittleness, distortion, or missing fins when the old impeller is inspected.
How often should an outboard impeller be replaced?
Inspect and replace the impeller according to the maintenance schedule for your specific Honda outboard. Replacement may be needed sooner when the engine is used in sandy, silty, salty, or otherwise demanding water conditions.
Is this an OEM Honda part?
No. This is an aftermarket replacement impeller designed for the listed Honda applications. It is not manufactured by Honda.
Safety & Important Information
- Verify the engine brand, horsepower, stroke, year range, model, and original impeller number before ordering.
- Do not operate an outboard without an adequate cooling-water supply.
- Inspect related water-pump components during installation and replace damaged parts as needed.
- Follow the service manual for your specific engine and use professional installation if you are not familiar with lower-unit service.
About Sea Sierra
- Marine Replacement Parts — Parts selected for common outboard maintenance and repair applications.
- Application-Focused Fitment — Check the listed model, horsepower, stroke, and year conditions before purchase.
- Support for Installation Planning — Confirm related service components before beginning a water-pump repair.
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